Patent US3687657A successfully refreshed from Google Patents.
EP0141676A2
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EP
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Power drive system
Assignee: Self Changing Gears Ltd
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Filing: 1984-11-07
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Granted: —
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Expires: 2004-11-07
Abstract
Abstract @ A power drive system for controlling the transmission of power from a prime mover such as a diesel engine (40) to a load such as the epicyclic transmission (50) of a track-laying vehicle comprises an hydraulically operable multiple dry-plate clutch (20), an electro-hydraulic valve (64) connected to operate the clutch, and a microprocessor control system (60). The microprocessor responds to the throttle setting by means of two L.V.D.T. sensors (61, 62), and to the differential clutch speed by two speed sensors (66, 67) and controls a fuel pump (41) by a stepper motor (42). During power take-up, the fuel pump is set to give maximum engine torque irrespective of throttle setting, and the microprocessor (60) causes the valve (64) to provide a pulse-width-modulated regular series of clutch-actuating pressure pulses having a predetermined frequency, the pulses causing the clutch to alternate at that frequency between zero and a predetermined maximum applying force, the pulse width variable, in response to the throttle setting, between 0 % and 100 % of the period corresponding to the said frequency. If the clutch fails to lock after a predetermined time, the power take-up procedure is recommenced. If the clutch does lock, the pulse width is set at 100 % and fuel pump control reverts to correspondence with throttle demand.
Inventors
- 👤 Harry Willetts
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 03:23
CPC Classifications
B; B60; B60W; B60W10/00; B60W10/04; B60W10/06; B60W10/02; B60W30/00; B60W30/18; B60W30/18009; B60W30/18027; B60W30/1819; B60W2510/00; B60W2510/02; B60W2510/0241; B60W2540/00; B60W2540/10; B60W2710/00; B60W2710/06; B60W2710/0616; F; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
124 words
A power drive system for controlling the transmission of power from a prime mover to a load, comprising an hydraulically operable multiple dry-plate clutch connectable in operation between the prime mover and the load, electro-hydraulic valve means connected to operate the clutch, and an electronic control system, responsive to a control signal representative of the degree of clutch slip, to cause the valve means to apply a pulse-width-modulated regular series of pressure pulses having a predetermined frequency, the pulses causing the clutch to alternate at that frequency between zero and a predetermined maximum applying force, the pulse width being set by the control system and variable, in response to the control signal, between 0% and 100% of the period corresponding to the said frequency.
Claim 2
Dependent Claim
124 words
A power drive system for controlling the transmission of power from a prime mover to a load, comprising an hydraulically operable multiple dry-plate clutch connectable in operation between the prime mover and the load, electro-hydraulic valve means connected to operate the clutch, and an electronic control system, responsive to a control signal representative of the degree of clutch slip, to cause the valve means to apply a pulse-width-modulated regular series of pressure pulses having a predetermined frequency, the pulses causing the clutch to alternate at that frequency between zero and a predetermined maximum applying force, the pulse width being set by the control system and variable, in response to the control signal, between 0% and 100% of the period corresponding to the said frequency.
Claim 3
Dependent Claim
40 words
A power drive system in accordance with Claim 1, wherein the clutch has a plurality of interleaved driving and driven plates, on to one of each pair of the opposing faces of which is bonded a plurality of friction segments.
Claim 4
Dependent Claim
19 words
A power drive system in accordance with Claim 2, wherein the friction segments are sintered bronze and/or ceramic material.
Claim 5
Dependent Claim
86 words
A power drive system in accordance with Claim 1,2 or 3, wherein the clutch comprises a casing attached rigidly to an input shaft adapted for connection to the prime mover, the casing also attached to a set of driving plates within the casing, a set of driven plates interleaved with the driving plates and rigidly attached to an output shaft adapted for connection to the load, and a plurality of hydraulic cylinders arranged within the casing when pressurised hydraulically to force the plates into frictional engagement.
Claim 6
Dependent Claim
28 words
A power drive system in accordance with Claim 4, wherein the input shaft drives an hydraulic fluid pump connected to provide the said hydraulic pressure to the cylinders.
Claim 7
Dependent Claim
59 words
A power drive system in accordance with any of Claims 1 to 5, wherein the control system comprises sensor means detecting the relative rotational speeds of the input and output clutch shafts, and a microprocessor responsive to a signal from the speed sensor representative of the differential speed to determine the said pulse width as a function of time.
Claim 8
Dependent Claim
59 words
A motor vehicle comprising a power drive system in accordance with any preceding claim, the clutch being connected between the vehicle engine and the vehicle transmission, and further comprising a throttle control, the control system responding to the throttle setting and to the differential rotational speed of clutch input and output shafts to set the said pulse width accordingly.
Claim 9
Dependent Claim
72 words
A vehicle in accordance with Claim 7, comprising a fuel pump and means for controlling the rate of flow of the fuel pump, the control system providing a signal to the fuel pump control means to vary the flow rate in correspondence with throttle demand when the clutch is locked, but independently of the throttle such as to give maximum prime mover torque during the period that there is some clutch slip.
Claim 10
Independent Claim
90 words
A method of controlling a multiple dry-plate clutch connected to control power transmission from a prime mover to a load, by applying to a plurality of hydraulic cylinders within the clutch a pulse-width-modulated regular series of pressure pulses having a predetermined frequency, the pulses causing the clutch to alternate at that frequency between zero and a predetermined maximum applying force, the pulse width being set by the control system and variable, in response to the control signal, between 0% and 100% of the period corresponding ! to the said frequency.
Claim 11
Independent Claim
90 words
A method of controlling a multiple dry-plate clutch connected to control power transmission from a prime mover to a load, by applying to a plurality of hydraulic cylinders within the clutch a pulse-width-modulated regular series of pressure pulses having a predetermined frequency, the pulses causing the clutch to alternate at that frequency between zero and a predetermined maximum applying force, the pulse width being set by the control system and variable, in response to the control signal, between 0% and 100% of the period corresponding ! to the said frequency.
Claim 12
Dependent Claim
34 words
A method in accordance with Claim 9, including the steps of detecting the differential rotational speeds of input and output clutch shafts by means of a sensor, and varying the said pule width accordingly.
Claim 13
Dependent Claim
30 words
A method in accordance with Claim 10, including the step of detecting the setting of a throttle controlling the demand on the load, and varying the said pulse width accordingly.
Claim 14
Dependent Claim
116 words
A method in accordance with Claim 9, 10 or 11, of controlling the clutch in the event that clutch slippage is required, comprising the steps of:- (i) causing the prime mover to develop maximum torque; (ii) varying the said pulse width between 0% and 100% in correspondence with inrottie demand, and simultaneously monitoring the differential clutch speed; (iii) in the event that the differential speed reaches zero within a predetermined period from the start, switching instantly to 100% pulse width; and (iv) in the event that the differential speed does not reach zero within the predetermined time, so that the clutch still slips, reducing the pulse width to 0% and recommencing the method at step (ii).
Claim 15
Dependent Claim
58 words
A method in accordance with Claim 12, comprising the step of controlling the setting of a fuel pump supplying fuel to the prime mover such that the prime mover develops its said maximum torque throughout the period of clutch slippage, but such that the fuel pump setting corresponds directly to the throttle setting when the clutch is locked.
References Cited (Backward Citations)
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